About this world
HD 22496 b is a sub-Neptune orbiting HD 22496, an orange dwarf (type K5/M0V) 44.3 light-years from Earth. It is about 2.2 times the size of Earth (its size estimated from its mass), with at least 5.6 Earth masses (a minimum, measured by radial velocity). It completes an orbit every 5.09 days at 0.051 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 573 K (300 °C): far too hot for liquid water on its surface. At its size it almost certainly keeps a deep envelope of hydrogen and helium.
It was discovered in 2021 by radial velocity with Paranal Observatory. The star wobbles toward and away from us, Doppler-shifting its spectrum.